Receive circuit for minimizing channels in ultrasound imaging

Abstract

Receive circuits and associated methods are provided for ultrasound imaging. Both subarray mixing and time division multiplexing are provided with a same circuit. Components of the receive circuit respond to either phasing or time slot information to implement subarray mixing or time division multiplexing. A network of switches allows combination of signals from different elements to form different sub-apertures. A controller minimizes power consumption while outputting the desired phase or time division multiplexed information by gating a clock to various registers. Each of the registers corresponds to different groups of transducer elements. For loading new phasing information, the clock is turned on to the desired register. Duration operation of the receive circuit, the clock is gated off. The register outputs the previously loaded values in a static state without clocking. Preamplification for either of time division or subarray mixed signals is provided using a variable gain amplifier with a common mode feedback. The common mode feedback provides for a constant operating point despite changes in the desired amount of gain.

1. A controller for a transducer probe of an ultrasound system, the controller comprising:
 a plurality of control modules comprising separate devices; 
 a clock source connected with each of the plurality of control modules; and 
 a clock enable controller connected with each of the plurality of control modules, the clock enable controller operable to prevent source clocking of at least one of the plurality of control modules and to enable the source clocking of the at least one of the control modules at other times, the prevention operable to avoid power dissipation by disabling any variable operation of the at least one of the control modules, the source clocking being separate from timing control signals used in operation of the control modules. 
 
     
     
       2. The controller of  claim 1  wherein the plurality of control modules comprise a plurality of registers and wherein the clock enable controller is operable to enable clocking for loading the plurality of registers and disable clocking during operation of a controlled receive circuit. 
     
     
       3. The controller of  claim 2  wherein the controlled receive circuit comprises:
 a plurality of paths connected with a respective plurality of transducer elements; and 
 a summer connected with the plurality of paths; 
 wherein at least one of the plurality of paths has a first component operable differently for each of at least two different sub-aperture modes. 
 
     
     
       4. The controller of  claim 3  wherein the first component comprises a plurality of switches, a first combination of switch connections operable for a first of the at least two different sub-aperture modes and a second combination of switch connects operable for a second of the at least two different sub-aperture modes. 
     
     
       5. The controller of  claim 4  wherein the plurality of switches comprises four switches, first and third switches connectable with a first input, second and fourth switches connectable with a second input, the second input being an inverse of the first input, the first and fourth switches connectable with a first output and the second and third switches connectable with a second output. 
     
     
       6. The controller of  claim 5  wherein the first and second switches are controllable in unison and the third and fourth switches are controllable in unison, the first sub-aperture mode corresponding to switching between (i) opening the third and fourth switches while closing the first and second switches and (ii) vice versa, the second sub-aperture mode corresponding to switching between (i) opening the third and fourth switches while closing the first and second switches and (ii) closing the first, second, third and fourth switches. 
     
     
       7. The controller of  claim 3  wherein the path comprises a single ended input amplifier having differential outputs connected with the first component and a differential input amplifier with a single ended output connected with the first component. 
     
     
       8. The controller of  claim 7  wherein the single ended input amplifier comprises a variable gain amplifier with a common mode feedback. 
     
     
       9. The controller of  claim 3  wherein each of the plurality of paths includes at least one component that is operable differently for each of the at least two different sub-aperture modes;
 further comprising: 
 at least one additional summer associated with the plurality of paths; and 
 a plurality of switches connected between (i) the paths and (ii) the summer and additional summer, the plurality of switches operable to selectively connect each of the paths to either of the summer and the additional summer. 
 
     
     
       10. The controller of  claim 1  wherein the clock enable controller comprises a serial interface. 
     
     
       11. The controller of  claim 1  wherein the control modules are operable to output a phase selection for each of a plurality of mixing circuits; and
 further comprising: 
 an element control operable to output a control signal that varies as a function of a selected one of at least two modes of operation. 
 
     
     
       12. The controller of  claim 11  wherein the mixing circuits are operable to mix an input signal with a local oscillator signal in a sub-array mixing mode and are operable to output the input signal in a selected time slot in a time division multiplexing mode. 
     
     
       13. The controller of  claim 12  wherein the mixing circuits comprise switches, the switches operable to open and close corresponding to the local oscillator signal in the sub-array mixing mode and the switches operable to open and close corresponding to the selected time slot in the time division multiplexing mode. 
     
     
       14. The controller of  claim 1  further comprising:
 a transducer probe housing connectable with an ultrasound imaging system; 
 wherein the controller is within the transducer probe housing. 
 
     
     
       15. A method of controlling operation in an ultrasound transducer, the method comprising:
 (a) selecting one of at least two different processes for each of a plurality of channels; 
 (b) outputting a signal responsive to the selection of (a) to each of the plurality of channels; 
 (c) performing (b) with a plurality of control modules, each control module being a device corresponding to a different group of elements; and 
 (d) disabling a source clock signal to at least one of the plurality of control modules during operation of the ultrasound transducer, the disabling preventing change in output of the at least one of the plurality of control modules during the operation of the ultrasound transducer, the source clock signal being separate from timing control signals used in operation of the control module. 
 
     
     
       16. The method of  claim 15  wherein (a) comprises selecting between mixing and multiplexing. 
     
     
       17. The method of  claim 16  wherein (a) comprises selecting mixing and wherein (b) comprises outputting a local oscillation signal having a first selected phase for a first of the plurality of channels and outputting the local oscillation signal having a second selected phase, different than the first selected phase, to a second of the plurality of channels. 
     
     
       18. The method of  claim 16  wherein (a) comprises selecting multiplexing and wherein (b) comprises outputting a respective time slot pulse for each of the plurality of channels in the sub-aperture.